US Patent 7503526 Space transportation node including tether system

A transportation node system orbits a celestial body. The node system includes a truss having two ends, the truss rotating around its center of mass while orbiting the celestial body. The truss stores payloads. The node system also includes tether tips, each attached to one end of the truss via a tether so that each tether tip can extend from the truss and retract to the truss for transfer of payloads. The tether runs through the length of the truss and connects to each tether tip, each tether tip being capable of engaging payloads. The node further includes at least one tether cable reel that reels in and reels out the tether so the tether tips can extend from and retract to the truss.